Operating unit for a device, in particular for a vehicle component

ABSTRACT

The operating unit for a vehicle, in particular for a vehicle component, is provided with a housing ( 10 ) which has an operating element ( 12 ), such as a display for example, and is designed to be secured in a device, in particular in a vehicle dashboard. The operating element ( 12 ) is elastically mounted on the housing ( 10 ). An actuator ( 16 ) is additionally provided for mechanically exciting the operating element ( 12 ) when an operation of the operating element ( 12 ) has been detected. Finally, the operating unit also has a vibration compensating mass ( 20 ) which can be mechanically excited by the actuator or by one actuator ( 16 ) when an operation of the operating element ( 12 ) has been detected and/or which is mounted on the housing ( 10 ) and can be moved in order to substantially compensate for forces acting on the housing ( 10 ) when the operating element ( 12 ) is moved.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of copending U.S. patent applicationSer. No. 16/082,806, filed Sep. 6, 2018 (published as US 2019/0084423A1)to Pankratz et al., entitled “Operating Unit for a Device, in Particularfor a Vehicle Component,” which is a national stage filing of PCTapplication PCT/EP2017/056555, filed Mar. 20, 2017, which claimspriority to German Patent Application No. DE 10 2016 204 875.9 filed onMar. 23, 2016, all of which are incorporated herein by reference.

The invention relates to an operating unit for a device whichparticularly is a vehicle component. Particularly, the invention relatesto operating units with force compensation in active haptic feedbackoccurring by mechanical excitation of an operating element of theoperating units, so that vibrations of the operating element caused bythe active haptic feedback are compensated or at least dampened and thuswill have no effect or merely a reduced effect on the environment of theoperating unit (e.g. instrument panel).

Display assemblies in vehicles are often provided with an active hapticfeedback so that the user will receive a—particularlytactile—confirmation of an operating input. In this respect, it is notdesired that the actuation of the feedback could generate aninadmissible dynamic force transmission into the environment of theoperating unit such as e.g. an instrument panel or a vehicle because,depending on the installation situation, this force transmission maylead to parasitic noise or vibration within the vehicle. Such amechanical decoupling is all the more important, the larger the mass ofthe mechanically excited operating element is.

Further, the haptic feedback shall be largely independent from theelasticity of the mounting in the vehicle.

A device provided with an active haptic feedback substantially consistsof an operating element with an operating field (e.g. touchscreen ordisplay) that, via a spring system, is elastically mounted to the devicehousing, an actuator for deflection of the operating element, and ahousing that is fixedly installed in the vehicle. In FIG. 1, the forcesat work in such a device configuration are represented. Referencenumeral 10 indicates the housing with the mass m₂. The connection orattachment of the housing 10 to the device environment (e.g. instrumentpanel) is symbolized by the spring damping system. The actuator isindicated by 16 and will mechanically excite the display or operatingelement 12 having the mass m₂. The movably mounted operating element 12is mounted to the housing 10 in a spring-elastic manner, which issymbolized by the spring-damping system 14. A sensor 19 detects anactuation of the operating element 12 (force sense function) andtransmits a signal to the evaluation and control unit 21 which controlsthe actuator 16 (force feedback function).

For generating the haptic feedback, the display will be deflected fromits rest position with a specific course of path x₁(t). The displayacceleration a₁(t) herein can assume values of more than 30 m/s², which,with a moved display mass m₁ of more than 0.5 kg and a normally smallhousing mass m₂, will result in a non-negligible dynamic force F₂(t)acting on the housing fastening structure in the vehicle.

In case of a “stiff” housing support or fastening structure e.g. on theinstrument panel (stiff spring system c₂, d₂), this temporallyfast-changing force may happen to cause inadmissible noises orvibrations in the vehicle.

In case of a “soft” fastening of the housing (soft spring system c₂,d₂), however, compliance with the mounting tolerances of the device inthe vehicle will pose difficulties. Further, due to the presence of afurther degree of freedom, namely the housing movement x₂(t) and thusalso additional natural frequencies in the system, the adjusting of therequired actuator force development F_(Akt)(t) will, depending on thecircumstances, not be possible.

From US-A-2004/0075676, there is known a laptop with haptic feedback forthe touchpad of the laptop. Herein, the touchpad is mechanically excitedby a piezo actuator and itself is resiliently supported on the housingof the laptop. The piezo actuator has a counterweight suspended on itwhich, as a result of the expansion of the piezo actuator when thelatter is driven, will be displaced oppositely to the movement of thetouchpad. By way of this approach, however, it is not all too easilypossible to realize a pulse compensation and a compensation of thedynamic forces within the housing of the laptop.

It is an object of the invention to provide a concept for an operatingunit with active haptic feedback that is improved with respect to thegeneration of parasitic noises and vibrations, respectively.

For achieving the above object, there is proposed, according to theinvention, an operating unit for a device, e.g. for a vehicle component,particularly a man-machine interface (MMI or HMI), said operating unitbeing provided with

-   -   a housing which comprises an operating element having an        operating panel such as e.g. a touchscreen or touchpad or        display, and which is provided for attachment in a device,        particularly in a vehicle dashboard or vehicle center console,    -   wherein the operating element is elastically mounted on the        housing,    -   a sensor for detection of an actuation of the operating element,    -   an actuator for mechanical excitation of the operating panel        occurring upon detection of an operation of the operating        element, and    -   a compensating weight,    -   wherein the compensating weight is adapted to be mechanically        excited by said, or an, actuator upon detection of an operation        of the operating element, and is elastically mounted in and/or        on the housing and/or is elastically mounted at the operating        element,    -   wherein the compensating weight is movable to substantially        compensate a movement of the housing upon activation of the        actuator mechanically exciting the operating element, or    -   wherein, in other words, the compensating weight is movable in a        manner substantially compensating and/or preventing and/or        damping the forces acting on the housing due to the movement of        the operating element occurring upon activation of the actuator,        namely particularly actively by the actuator exciting the        operating element or by an actuator assigned to the compensating        weight.

Thus, according to the invention, the compensating weight is elasticallyfastened to the housing. The compensating weight is moved either by theactuator exciting the operating element or by a separate actuatorassigned to the compensating weight.

It is suitable of if the compensating weight is designed as a part ofthe actuator mechanically exciting the operating element, e.g. as anintegral component of the stator of a tie-rod or plunger-coilelectromagnet actuator. Instead of being designed as such anelectromagnet actuator, the actuator can also be designed as a piezoactuator. However, the compensating weight can also be provided as anelement separate from said actuator. In each case, the compensatingweight is elastically supported on the housing and thus is elasticallypropped relative to the housing.

Particularly, it is of advantage if the compensating weight is movablewith a phase shift of substantially 180° and thus in the oppositedirection to the excitation movement of the operating element whereinthe movement stroke of the compensating weight is selected underconsideration of at least the relation of the mass of the operatingelement to the mass of the compensating weight. If, for instance, themass of the compensating weight is half the mass of the operatingelement, the movement stroke of the compensating weight is twice aslarge as the movement stroke of the operating element. In practice, theoperating element is deflected e.g. by 0.1 mm or by a few 1/10 mm. Ifthe mass of the operating element is e.g. 0.5 kg, it would be possible,for the inventive compensation of forces acting from the operating unittoward the outside, to use e.g. a compensating weight having a mass of50 g and a movement stroke of 1 mm or a few mm.

Further, it is of advantage for a largest possible compensation offorces if the natural frequencies of the spring-mass damping system ofthe elastic coupling of the operating element to the housing and thenatural frequency of the spring-mass damping system of the elasticcoupling of the compensating weight to the housing or to the operatingelement are equal or substantially equal. Herein, in the framework ofthe invention, the phrase “substantially equal” is to be understood asdenoting a deviation from the natural frequency of 50%, particularly40%, preferably 30% and most preferably 20% or 10%.

The operating unit of the invention can be designed as display andoperating unit.

The invention will be described hereunder in greater detail and withreference to the drawing. In the individual Figures, the following isshown:

FIG. 1 is a schematic representation of the forces occurring in anoperating unit with active haptic feedback according to the state of theart,

FIG. 2A is a schematic representation of the forces occurring when usinga compensating weight as a compensating mass in the manner provided bythe invention,

FIG. 2B is a schematic representation of an alternative embodiment usinga separate actuator for the compensating weight and

FIG. 3 is a schematic representation of the design of acounterforce-free haptic feedback in an operating unit.

According to the invention as shown in FIG. 2A, there is proposed theuse of an elastically supported (see spring-mass damping system 22)movable countermass 20 between the actuator 16 and the housing 10 forbalancing the forces acting on the housing 10. The actuation of theoperating element 12 is detected by means of the actuation sensor 19.Thereupon, via an evaluation and control unit 21 which receives signalsfrom the actuation sensor 19 and transmits control signals to theactuator 16, the actuator 16 will be controlled. In an alternativeembodiment of FIG. 2B, a separate actuator 17 excites countermass 20,which acts as the counter weight.

In case of a corresponding design of the additional spring-mass dampingsystem 22 and c₃, d₃, m₃, respectively, the resulting force F₂(t) actingon the vehicle can be eliminated. (The static forces generated bygravitation do not play a role in the generating of noises orvibrations).

For a randomly predetermined display deflection x₁(t), the deflectionx₂(t)/motion of the device housing and thus also the force F₂(t) actingon the device fastening structure can be eliminated under the followingconditions:

${c_{3} = {c_{1}\frac{m_{3}}{m_{1}}}},\mspace{14mu}{d_{3} = {d_{1}\frac{m_{3}}{m_{1}}}}$

From this, there results the deflection of the countermass 20:

${x_{3}(t)} = {{x_{1}(t)}\frac{m_{1}}{m_{3}}}$

Under these conditions, also the elasticity of the device fasteningstructure 18 will have no influence on the haptic feedback. Thecountermass 20 and m₃, respectively, is normally restricted by thedemands posed on the installation space and is smaller than the displaymass m₁. In the ideal case, it can be realized as a part of the actuator16.

The present invention makes it possible

-   -   to generate a haptic feedback on mass-carrying surfaces without        causing effects of dynamic forces on the environment,    -   to generate a haptic feedback in an operating device that is        independent from the elasticity of the device fastening        structure.

In FIG. 3, a device with counterforce-free haptic feedback isschematically outlined.

In the illustrated example, the actuator 20 is designed as a tie-rodelectromagnet and comprises a stack of stator laminations, elasticallysupported on housing 10 and having an actuator coil, i.e. a stator 26and an armature core tightly coupled to the operating element 12, i.e.an armature 28. The stator 26 forms a movable countermass 20 orcomprises the same. When setting the air gap, shown at 30, in thetie-rod electromagnet, the maximum deflection of the display 10 and ofthe countermass 20 relative to each other has to be considered. Thestator 26 is supported elastically (spring-mass damping system 22) onthe housing 10 but alternatively can also be elastically coupled to theoperating element 12. The operating element guide means is schematicallyrepresented at 32. The housing 10 is fastened to the vehicle 24 (e.g. atthe instrument panel of the vehicle).

The invention has been described above by way of an operating unit foruse in a vehicle but, as initially mentioned, is also applicable quitegenerally for operating units all of types of devices or systems. Indevices that comprise more than one operating surface with hapticfeedback, each operating surface can be mechanically excitedindependently from the at least one other operating surface in themanner provided by the invention. Thus, each operating surface comprisesits own dedicated balance mass so as to be able to compensate for deviceforces and movements acting toward the outside, which are induced bymechanical excitation of any one of the operating surfaces.

LIST OF REFERENCE NUMERALS

-   10 housing-   12 operating element-   14 spring damping system of the elastic coupling of the operating    element to the housing-   16 actuator-   17 separate actuator-   18 spring damping system of the (elastic) coupling of the housing to    the vehicle-   19 actuation sensor-   20 counterweight-   21 evaluation and control unit-   22 spring damping system of the elastic coupling of the    counterweight to the housing and/or the operating element-   24 vehicle or operating panel of the vehicle-   26 stator of the tie-rod electromagnet designed as actuator-   28 armature of the tie-rod electromagnet-   30 air gap of the tie-rod electromagnet-   32 guide means of the operating panel for the motion upon haptic    feedback-   m₁ mass of the operating panel-   x₁(t) deflection of the operating panel-   F_(Akt)(t) actuator force development-   F₁(t) force of the operating panel acting on the housing 10 upon    excitation of the operating panel (F₁(t)=F_(Akt)−m₁×a₁)-   c₁ spring constant of the elastic coupling of the operating panel on    the housing-   d₁ damping of the elastic coupling of the operating panel on the    housing-   m₂ mass of the housing-   x₂(t) deflection of the housing resulting from the force exerted by    the mechanically excited operating panel-   F₂(t) force acting on the housing fastening structure-   m₃ mass of the counterweight-   x₃(t) deflection of the counterweight-   F₃ force acting on the housing by the counterweight-   c₃ spring constant of the elastic coupling of the counterweight to    the housing-   d₃ damping of the elastic coupling of the counterweight to the    housing

What is claimed is:
 1. An operating unit for a device comprising anoperating element having an operating panel, a housing wherein thehousing is attached to the device, and wherein the operating element iselastically mounted on the housing, a sensor for detection of anactuation of the operating element, an actuator for mechanically drivingthe operating element its actuation, a compensating weight, and aseparate actuator for mechanically driving the compensating weight upondetection of the actuation of the operating element, wherein thecompensating weight has an elastic mounting to the housing and/or anelastic mounting to the operating element, wherein the compensatingweight is configured to move to substantiallycompensate for a relativemovement of the housing and the operating element to correspondinglydampen transmission of dynamic forces between the housing and theoperating element.
 2. The operating unit according to claim 1, whereinthe compensating weight is separated from said separate actuator.
 3. Theoperating unit according to claim 1, wherein the compensating weightmoves with a phase shift of substantially 180° to the relative movementof the operating element, wherein a movement stroke of the compensatingweight is selected under consideration of at least the a ratio of themass of the operating element to the mass of the compensating weight. 4.The operating unit according to claim 1, wherein the operating elementinclusive of its elastic mounting to the housing has a firsteigenfrequency and the compensating weight inclusive of its elasticmounting to the operating element and/or to the housing has a secondeigenfrequency, wherein the first and the second eigenfrequencies areequal or substantially equal.
 5. The operating unit according to claim1, wherein the separate actuator is a tie-rod or plunger-coilelectromagnet comprising a stator and an armature.
 6. The operating unitaccording to claim 5, wherein the stator and/or the armature of theseparate actuator is kinematically coupled to the compensating weightand forms or comprises the compensating weight.
 7. The operating unitaccording to claim 1, wherein the operating element further comprises adisplay function.
 8. The operating unit according to claim 2, whereinthe compensating weight moves with a phase shift of substantially 180°to the relative movement of the operating element, wherein a movementstroke of the compensating weight is selected under consideration of atleast the ratio of the mass of the operating element to the mass of thecompensating weight.
 9. The operating unit according to claim 1, whereinthe device is a man-machine interface in a vehicle component.
 10. Theoperating unit according to claim 9, wherein the vehicle component is adashboard and/or a center console.
 11. The operating unit according toclaim 1, wherein the operating panel is a touchscreen, a touchpad, adisplay or a combination thereof.
 12. The operating unit according toclaim 1, wherein the compensating weight is part of said separateactuator.
 13. The operating unit according to claim 12, wherein thecompensating weight moves with a phase shift of substantially 180° tothe relative movement of the operating element, wherein a movementstroke of the compensating weight is selected under consideration of atleast the ratio of the mass of the operating element to the mass of thecompensating weight.